1. Field of the Invention
The present invention generally relates to a signal transmission device, and more particularly to a rotary type signal transmission device which is expanded and retracted through pressing.
2. Description of Related Art
Modern 3C electronic products such as digital cameras, digital video cameras, mobile phones, notebook personal computers or tablet personal computers, etc. with advantages of light weight, small size, powerful functions and easy to carry are widely loved and used by consumers.
Portable electronic products such as digital cameras and digital video cameras usually need additional signal transmission line to connect other electronic products or systems to transmit data such as photographs or video files or to recharge batteries so that users have to carry the additional signal transmission line beside the portable electronic products. Thus the user who does not have the additional signal transmission line in hand cannot proceed file transfer or battery recharge and it is inconvenient for the user. For the convenience of the user, there is a trend of directly connecting portable electronic product to other electronic system such as a computer without using additional signal transmission line to proceed file transfer or battery recharge so as to avoid the trouble of unable connecting to the computer due to lack of any signal transmission line in hand.
Thus the invention provides a built-in extendable signal transmission device of a portable electronic product which can enable the user to proceed file transfer or battery recharge any time without any signal transmission line and effectively improve the conveniency of the portable electronic product.